1. Field of the Invention
The present invention relates to an electronic circuit apparatus for transmitting signals through a bus. Further, the present invention also relates to a semiconductor device for generating a predetermined stable voltage.
2. Description of the Related Art
An electronic circuit apparatus is arranged on a printed board (mother board). The mother board, for example, comprises an MPU (microprocessor unit), a data transmission bus (data bus lines), a memory unit (memory modules), various extended boards, and the like.
Clock frequencies of MPUs today are in excess of 100 MHz. Further, DRAMs (dynamic random access memories), used as a main memory, are built as the data server to cache memories in modern microprocessor systems. They operate mostly in burst-mode rather than in random access mode, in order to re-write the data in cache memories. High bandwidth memories such as SDRAMs (synchronous DRAMs) are thus useful for high-speed implementation in the burst-mode, along with high-speed I/O circuits for the bus interface.
Therefore, high performance I/O circuits for fast memory such as SDRAMs are now required. The problems of the prior art relating to a first aspect of the present invention (electronic circuit apparatus for transmitting signals through a bus) will be explained hereafter in detail with reference to the accompanying drawings.
On the other hand, recently, semiconductor devices must be compact and operate at a high speed and low power consumption. To realize this, it is necessary to provide the semiconductor devices with a high-speed clock signal and a low source voltage.
Namely, it is necessary to provide a semiconductor circuit capable of providing a stable source voltage as a cell plate voltage for a semiconductor memory such as a DRAM, or as a reference voltage for a small-amplitude I/O device. The problems of the prior art relating to a second aspect of the present invention (semiconductor device for generating a predetermined stable voltage) will be also explained hereafter in detail with reference to the accompanying drawings.